1. Field of the Invention
The present invention relates to high-voltage electrical equipment, and particularly to a high-voltage fuse element retaining device for preventing a fuse element from discharging away from a fuse barrel after the fuse is blown.
2. Description of the Related Art
Single-phase and three-phase electrical power is delivered to commercial, industrial and residential users through a system commonly known as the “power distribution grid”, which generally includes such components as generating plants, transformers, and electrical power lines. These lines generally include both transmission lines, which typically have AC voltages in the range of about 70,000 V to about 750,000 V, and distribution lines, which typically have AC voltages in the range of about 2,300 V to about 50,000 V. Utility workers often must either service or replace high voltage power lines in the course of regular maintenance, despite the inherent danger in working with such high voltages. These service and repair duties often include the replacement of power line fuses, which, when operable, can carry hundreds of amperes of electrical current and, even when inoperable, may form part of an energized circuit carrying thousands of volts of electrical potential, which may still be available at the load side of the fuse.
Generally, power line fuses are located at or near the tops of power poles, positioning these fuses over thirty feet above the surface of the ground. Each fuse is generally carried in a fuse holder, which is commonly referred to as a “fuse barrel assembly”, typically including a fuse holder barrel and providing an interface between the fuse and the fuse block connected to the power line. The bottom end of the fuse barrel assembly has a hinge assembly that includes an ejection assembly for automatically releasing the top end of a blown fuse from a fuse block, along with a pair of pivot pins (typically one pin on each side of the hinge assembly) that are adapted to fit into slots formed on the bottom of the fuse block. The top end of the fuse barrel assembly typically includes a hoop, a pull-ring or a similar structure. When the fuse element is blown, the fuse element is thrown by conversion of electrical energy into kinetic energy, becoming a projectile and traveling at a high rate of speed toward the ground. Any utility workman, utility employee or other individual in the vicinity of this projectile can be seriously injured.
Thus, a fuse element retaining device solving the aforementioned problems is desired.